        public class e9 {
        private static final int TIMES = 100000;
        public static void main(String[] args) {
            e9.testString();
            e9.testStringBuilder();
            e9.testStringBuffer();
        }
        public static  void testString(){
            long starTime = System.currentTimeMillis();
            String str ="";
            for(int i = 0;i<TIMES;i++){
                str +="test";
            }
            long endTime = System.currentTimeMillis();
            System.out.println("String test usedtime:"+(endTime-starTime));
        }
        public static  void testStringBuffer(){
            long startTime = System.currentTimeMillis();
            StringBuffer str = new StringBuffer();
            for (int i = 0; i<TIMES;i++){
                str .append("test");
            }
            long endTime = System.currentTimeMillis();
            System.out.println("StringBuffer test usedtime:"+(endTime-startTime));
        }
        public static  void testStringBuilder(){
            long startTime = System.currentTimeMillis();
            StringBuilder str = new StringBuilder();
            for (int i = 0; i<TIMES;i++){
                str .append("test");
            }
            long endTime = System.currentTimeMillis();
            System.out.println("StringBuilder test usedtime:"+(endTime-startTime));
        }
    }
